Container with locking lid

ABSTRACT

A container comprising a bottom portion comprising a rectangular bottom section and a front wall, rear wall, and two opposing side walls extending from the edges of the bottom section, the bottom portion further comprising a first locking projection extending from a first corner and a second locking projection extending from a second corner, and a top portion comprising a rectangular top section and a front wall, rear wall, and two opposing side walls extending from the edges of the bottom section, the top portion further comprising a first opening configured to receive the first locking projection and a second opening configured to receive the second locking projection.

TECHNICAL FIELD

This invention relates generally to containers, and more specifically relates to containers with locking lids.

BACKGROUND

Prepared food products are frequently sold in disposable containers. Enclosed containers are used to insulate hot food products, reduce spills, and shield the food products from contaminants. Closed containers are frequently releasably secured in a closed position.

Various disposable containers are currently available with a locking mechanism for securing the lid to the base. Operating the locking mechanism is an additional step for the food server after closing the container. Common locking mechanisms require the server to manipulate a tab in one of the base or lid through a slit in the other of the base and lid. This manipulation takes a few seconds, which adds up to a large investment of time over the high quantity of products sold by fast food and concession stand style businesses.

SUMMARY OF THE INVENTION

In one form, a container is provided that includes a locking mechanism that releasably secures top and bottom portions of the container together when the container is closed without the need for undertaking an additional locking step. More particularly, one of the top and the bottom portions includes a plurality of resilient projections. The other of the top and the bottom portions includes a plurality of through openings or apertures. The projections and through openings are arranged and configured such that when the top and bottom portions are closed together, the projections are received by an interference fit in the respective through opening to resist removal of the top portion from the bottom portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of a container having a bottom portion with upward projections extending through openings in a top portion to form an interference fit therewith with the top portion closed onto the bottom portion.

FIG. 2 is a perspective view of the bottom portion of the container of FIG. 1 showing the projections at corners of the upstanding walls.

FIG. 3 is a perspective view of the top portion of the container of FIG. 1 showing the openings at the junctures of a top panel and depending walls therefrom.

FIG. 4 is a plan view of a blank for forming the bottom portion of FIG. 2 showing the fold lines for forming the erected bottom portion.

FIG. 5 is a plan view of a blank for forming the top portion of FIG. 3 showing the fold lines for forming the erected top portion.

Elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale or to include all features, options or attachments. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. Certain actions and/ or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. The terms and expressions used herein have the ordinary technical meaning as is accorded to such terms and expressions by persons skilled in the technical field as set forth above except where different specific meanings have otherwise been set forth herein.

DETAILED DESCRIPTION

A two-piece container includes a bottom portion and a top portion. The bottom portion has a bottom panel with upstanding walls extending upwardly from the peripheral edges which together form an internal cavity open at the top. The top portion has a top panel. At least one of the top portion and the bottom portion includes locking projections projecting therefrom. The projections extend obliquely to the bottom and/or top panel. The locking projections are received within apertures in the other of the top portion and bottom portion when the top portion and bottom portion are pressed together to close the container.

In some forms, the upstanding walls extend from the edges of the bottom panel at an outward incline obliquely to the bottom panel. Adjacent ends of upstanding walls are coupled to form a corner therebetween. Each corner includes a generally upward extending projection extending above the top edge of the upstanding walls. The projection also can extend obliquely to the bottom panel, preferably at the same angle of inclination as the underlying wall or walls from which it projects.

The top portion has a top portion or top panel having a plurality of apertures, each aperture arranged and corresponding to a projection of the bottom portion. In some forms, the top portion has depending walls extending downwardly from peripheral edges of the top panel which together form an internal cavity open at the bottom. The depending walls preferably extend obliquely to the top panel. The top panel can have a generally polygonal shape, such as a rectangular shape, where the panel has four corners.

One exemplary container will now be described. Turning to FIGS. 1-3, the container 100 includes a base or bottom portion 110 and a lid or top portion 150. The bottom portion 110 has a bottom panel 120 and upstanding sidewalls 112 extending from the peripheral edges 120 a-120 d of the bottom panel 120. Two or more resilient locking projections 138 extend upward from the top edges 112 a-112 d of the sidewalls 112. The locking projections 138 are inclined at an oblique angle 138 a relative to the bottom panel 120. As illustrated, the base 110 has four locking projections 138, although it is possible for as little as two locking projections 138 to be utilized. The locking projections 138 extend in different directions generally upwardly away from each other, such that the locking projections 138 are further apart from each other the higher up they are from the bottom portion 120.

The bottom portion 110 of the exemplary container 100 has a rectangular shape, such as a square, with a locking projection 138 located at each corner. The locking projections 138 each extend outward relative to the center of the container 100 as they extend upward from the walls 112. As shown, the locking projections 138 include a fold line along their longitudinal axis 113 a to increase the stiffness and resiliency of the resilient locking projections 138.

The sidewalls 112 of the bottom portion 110 can be angled to be inclined outwardly relative to the bottom panel 120 to form an angle therebetween as can be seen in FIG. 2. The angle of the sidewalls 112 is preferably equal to the inclined angle 138 a of the locking projections 138, such that the locking projections 138 transition smoothly to the sidewalls 112 without any bends therebetween. The locking projections 138 are formed at the corners 113 of the sidewalls 112 to extend therearound such that they are bent or folded about the axis 113 a to have a generally L-shaped cross section.

The acute angle 138 a between the longitudinal axis 113 a of the projections 138 and the horizontal 120a is in the range of between approximately 85 degrees and approximately 70 degrees. In a preferred form, the angle 138 a is in the range of between approximately 80 degrees and approximately 75 degrees. In the illustrated form, the angle 138 a is approximately 78 degrees.

The range of angles described above are exemplary only and not intended to be limiting of any embodiment. For desirable performance, the angle selected should not be so extreme that it is difficult to press the top portion 150 down onto the bottom portion 110 leading to the deformation described herein. On the other hand, the angle should not be so slight that the top portion is not held in place securely by the interference fit between the projections 138 in the bottom portion and the through openings or apertures 162 in the top portion. It should be noted that the choice of material for the container may affect the optimum angle 138 a selected for a particular application.

The top portion 150 has a flat top panel 160 having at least two apertures 162 with four apertures 162 being illustrated, one at each corner of the top panel 160. The apertures 162 are arranged and sized to receive the locking projections 138 when the top portion 150 is placed on the bottom portion 110 to close the container 100. The apertures 162 are closer to each other in a direction parallel to the top panel than the corresponding locking projections 138 in the same direction. As a result, the locking projections 138, sidewalls 112, and/or the top portion 150 deforms when the container 100 is closed in order for the projections 138 to pass through the apertures 162. Once the container 100 is fully closed, the resilient locking projections 138 and/or top portion 150 return to or toward their undeflected shape, necessitating them to be deflected or deformed again in order to open the container 100. The interference fit between the locking projections 138 and the top portion 150 secures the top portion 150 to the bottom portion 110, thus forming an interference lock. Two locking projections 138 are spaced in a direction parallel to the top and bottom panels from each other that are separated by a distance greater than the distance between opposite, outside edges of the apertures 162. In order for the locking projections 138 to pass through the apertures 162, the locking projections 138 must be deflected or deformed until the furthest points are at least as close together as the outside edges of the apertures 162. This deflection or deformation positions the locking projections 138 within the area defined by the apertures 162 such that pushing the top portion and base potion together into a closed position pushes the locking projections 138 through the apertures 162.

The top portion 150 preferably includes depending sidewalls 152 extending downward from the periphery of the top panel 160. The sidewalls 152 depend from the top panel 160 at an oblique angle such that the lower edge of the sidewalls 152 are further apart than the top corners 161. As the container 100 is closed, the locking projections 138 are deformed inward and guided into the apertures 162 by the sidewalls 152. The angled sidewalls 152 serve as wedges or ramps acting upon the locking projections 138. When a downward force is exerted on the top portion 150 to close it onto the bottom portion 110, the angled sidewalls 152 exert a portion of this downward force onto the locking projections 138 in a direction generally orthogonal to the surface of the sidewalls 152. This exerted force creates stress within the locking projections 138 causing them to deflect or deform inward to the point at which the outer most portions of the locking projections are within the area of the apertures 162 such that they can be received therein.

In the illustrated container 100, the top portion 150 has a rectangular shape. The apertures 162 are located proximate the corners 153 of the top portion 150 so as to correspond with the locking projections 138 located at the corners 113 of the bottom portion 110. The apertures 162 are located at the corners 161 such that there is no portion of top panel 160 along the outer perimeter of the apertures 162 between the apertures 162 and the sidewalls 152. This enables the projections 138 to be cammingly engaged by the sidewalls 152 to be deflected inwards for smoothly sliding into and through the apertures 162. Referring to FIG. 3, it can be seen that the apertures 162 extend partially through the top panel 160 and partially through the sidewalls 152.

The apertures 162 are generally L-shaped, with a first leg extending generally along a first sidewall 152 and the second leg extending generally along a second sidewall 152. Each leg of the apertures 162 is approximately 0.25 inches in width.

At each corner 113 of the bottom portion 110, a tab 114 is provided. As illustrated, two opposite sidewalls 112 include tabs 114 at both ends thereof. When constructed, the tabs 114 are folded relative to the respective sidewalls 112, such that they extend along the inner surface 112i of an adjacent one of the sidewalls 112. The locking projection 138 may be formed to extend upward from the sidewall 112 having the tab 114 such that a portion of the locking projection 138 extends from the tab 114. As a result, folding the tab 114 also folds the locking projection 138 to give it a generally L-shaped cross section. The folded tabs 114 are secured to the adjacent sidewalls 112 so that the bottom portion 100 is secured in its erected configuration. The tabs 114 are attached by an adhesive, such as a hot melt or cold melt adhesive. The adhesive can be a starch based adhesive or other type of adhesive usable in compostable, repulpable, and/ or recyclable containers.

The walls 152 of the top portion 150 are oblique to the top panel 160 such that they are slanted in a generally opposite direction as the walls 112 of the bottom portion 110. The bottom edges 153b of any pair of corners 153, whether adjacent to each other or diagonally spaced from each other, are spaced apart by a distance greater than or equal to the distance between the ends of the corresponding pair of projections 138. As such, the top portion 150 can be centered over the bottom portion 110 such that the tops of the projections 138 are covered by the top portion 150. Any pair of apertures 162, whether adjacent to each other or diagonally spaced from each other, are spaced apart by a distance less than the distance between the tips of the corresponding pair of projections 138.

As the top portion 150 is pressed down onto the bottom portion 110, the angled walls 152, 156 cammingly engage the projections 138 exerting an inward force causing them to deflect inwardly. The so deformed projections 138 are then able to pass through the apertures 162 with continued downward travel of the top portion 150 onto the bottom portion 110. Once the projections 138 extend through the apertures 162, the projections 138 can return toward their undeflected shape such that the tips of the projections 138 are spaced apart further than the corresponding apertures 162. The undeformed projections 138 form resilient locks that releasably secure the top portion 150 in place relative to the bottom portion 110.

In one form, the angle between the outside of the walls 152 of the top portion and the plane of the top panel 160 is equal to the angle 138 a or up to 5 degrees greater than the angle 138 a. For example, if the angle 138 a is 77 degrees, the angle of the walls 152, 156 is between 77 degrees and 82 degrees. In another embodiment, the angle of the walls 152 is at most 2 degrees greater than angle 138 a. The angles listed above increase tensional friction between the projections 138 and the top portion 150 without overly increasing the likelihood of damaging the container 100. If a lesser angle 138 a is used, the inward force exerted on the projections 138 increases, thus increasing the likelihood of the projections 138 folding over, reducing the resiliency of the projections 138 such that it does not return to its original static shape. Alternatively, the force may be great enough to damage the top portion 150, causing the sidewalls 152 to detach from each other and/or tear. Too great of an inward force can further cause the L-shaped cross section of the projections 138 to flatten such that they no longer align with the L-shaped apertures 162.

The preferred angles given above vary based on the material from which the container 100 is constructed. Containers 100 formed of more rigid materials have walls 112, 152 that are closer to perpendicular to the horizontal panels 120, 160 because the same amount of force deforms the projections 138 inward by a lesser amount.

Applying sufficient force to pull the top portion 150 upward relative to the bottom portion 110 causes the projections 138 to deform such that they pass through the apertures 162, allowing the top portion to be removed. Once the top portion is completely removed, the projections 138 again return to the static shape. The sufficient force is greater than the weight of the bottom portion, such that lifting an empty container 100 by the top portion 150 does not cause the bottom portion 110 and top portion 150 to separate from each other.

FIG. 4 illustrates a blank 210 for forming the bottom portion 110 described above. The blank 210 is a unitary and planar die-cut blank, preferably of a substrate or sheet of corrugated paper or of paperboard material. For example, the blank 210 may be formed of single or double faced micro-fluted sheets such as an “O”, “G”, “N”, “E” or “F” flute sheet. The die cut blank 210 includes scores 213 and 221 at which the blank 210 is folded to form the erected bottom portion 110. The angles 112 a, 116 a between the scores 213 or cuts 215 and scores 221 are obtuse. These angles are equal to the angles of the walls 112 relative to the bottom panel 120 when the bottom portion 110 is erected.

The scores 213 that form corners 113 are oblique to the scores 221. The scores 213 angle outward from the scores 221 at angles of 112 a along the sidewalls 112. Similarly the cut lines 215 angle outward from the scores 221 at an angle 116 a substantially equal to the angle 112 a. In a preferred form, the angles 112 a and 116 a are approximately equal to each other and are supplementary to the angle 138 a. In one form, the angles 112 a and 116 a are between 95 degrees and 110 degrees. In a preferred form, the angles 112 a and 116 a are between 100 degrees and 105 degrees. In the form shown, the angles 112 a and 116 a are approximately 102 degrees. As described above, the preferred angle is determined by the rigidity of the material forming the container 100. The angles given above are based on a paperboard container. Varying the material or the thickness of the material may affect the preferred angles.

When the blank 210 is erected to form the bottom portion 110, the tabs 114 are folded along the scores 213 so as to extend along the inner surface of the adjacent sidewalls 112. Adhesive is applied to the inner surface of the sidewalls 112 and/or the outer surface of the tabs 114 to secure the bottom portion 110 in an erect position. In some forms, the adhesive is compostable, such as a starch based adhesive, such that the container 100 is recyclable, compostable, and/or pulpable.

As described above, the projections 138 are at least partially dissected by scores 213 such that when the blank 210 is erected the sheet material forming the projections 138 is folded to form a generally L-shaped cross section. In alternative embodiments, the material forming the projections 138 is bent instead of folded to form projections having a generally C-shaped cross section.

FIG. 5 illustrates a blank 250 for forming the top portion 150 described above. The blank 250 is a unitary and planar die-cut blank, preferably of corrugated paper or of paperboard material. For example, the blank 250 may be formed of single or double faced micro-fluted sheets such as an “O”, “G”, “N”, “E” or “F” flute sheet. The die cut blank 250 includes cut lines 255 and scores 253 and 261 at which the blank 250 is folded to form the erected top portion 150. The angles 252 a and 256 a between the scores 253 and 261 and the cut lines 255 and scores 261 respectively are obtuse. These angles are equal to the angles of the sidewalls 152 relative to the top panel 160 when the top portion 150 is erected. The scores 253 and cut lines 255 are oblique to the scores 261 at angles 152 a and 156 a. In a preferred form the angles 152 a and 156 a are supplementary to the desired angle of the walls 152, 156 described above.

In one form, the angles 152 a and 156 a are equal to the angles 112 a and 116 a respectively or up to 5 degrees less than. In a preferred form, the angles 152 a and 156 a are between 2 degrees less than 112 a and 116 a respectively and equal to 112 a and 116 a respectively. In the embodiment illustrated by FIGS. 4-5, the angles 112 a and 116 a are approximately 102 degrees and the angles 152 a and 156 a are approximately 100 degrees.

The cut lines 255 are cut to separate adjacent sidewalls 152 and form form tabs 154. When the blank 250 is erected to form a top portion 150, the blanks are adhered, such as by a hot melt or cold melt adhesive, to the inner surface of the adjacent sidewalls 152. The adhesive secures the top portion 150 in an erected position.

While the exemplary container 100 only illustrates locking projections 138 extending from the bottom portion and apertures 162 in the top portion, it is understood that these could be switched such that locking projections extend from the top portion and are received in apertures of the bottom portion. In some forms, both the bottom portion and the top portion can include locking projections received in corresponding apertures in the other of the bottom portion and the top portion. These alternatives operate in the same manner by being configured such that the locking projections are received by the corresponding apertures when the top portion and bottom portion are pressed into a closed position and form an interference lock therewith.

In alternative embodiments, the container 100 is formed of materials other than paperboard or corrugated paper. For example, the container 100 could be formed of a plastic or composite. Instead of being assembled by folding die cut blanks as described above, a plastic or composite container would be molded, such as injection molded, to have the shape of the erected container 100 shown above.

In other alternatives, the container 100 has more or fewer projections 138. In preferred forms, the projections 138 are positioned at corners of the bottom portion 110 so as to be folded for additional strength and resiliency. Embodiments having additional projections may have a different shape, such as being hexagonal or octagonal instead of rectangular. Embodiments having fewer projections 138 may have fewer corners, such as a triangular shape, or may only have projections 138 on some of the corners of the bottom portion 110. Additionally, or alternatively, the projections 138 are located on the tops of curved walls instead of corners. For example, a container having a circular or oval shape can have generally C-shaped projections spaced along the rim of its sidewall.

In still further examples, the top portion 150 and bottom portion 110 of the container 100 are hingedly attached so as to have a clamshell configuration. For example, the container 100 is made of a single die cut blank with a score line separating the rear walls from each other. The projections 138 are located on the corners of the front wall so as to lock the top portion in a closed position. [Consider whether we need a drawing of this embodiment.]

In addition, one skilled in the art will appreciate variations in the above-described containers and related methods can be provided. For example, the angles 112 a and 152 a can vary from angles 116 a and 156 a respectively such that the projections 138 extend out more in one direction than the other. Additionally, one skilled in the art will appreciate that a variety of methods are contemplated in the description above. For example, methods of making a flexible laminate, bag, and/or insert and methods of using the same.

Those skilled in the art will recognize that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of the invention, and that such modifications, alterations, and combinations, are to be viewed as being within the scope of the invention. 

What is claimed is:
 1. A container comprising: a bottom portion including a bottom panel and upstanding walls extending upwardly from peripheral edges of the bottom panel; a top portion including a top panel; first and second locking projections projecting from one of the bottom portion and top portion; and first and second through openings of the other of the bottom portion and the top portion for receiving the respective first and second locking projections, the locking projections and through openings being arranged and configured so that as the bottom portion and top portion are closed together, the locking projections are received by an interference fit in the respective through openings to resist removal of the top portion from the bottom portion.
 2. The container of claim 1 wherein the first and second locking projections are resiliently flexible to allow the projections to resiliently deflect as the projections are received in the corresponding through openings.
 3. The container of claim 1 wherein the first and second locking projections project upward from the bottom portion and the first and second through openings extend through the top portion.
 4. The container of claim 1 wherein the first locking projection and the second locking projection are inclined relative to the bottom panel.
 5. The container of claim 4 wherein the at least one of the upstanding walls is inclined relative to the bottom panel at the same inclination as the locking projections relative to the bottom panel.
 6. The container of claim 1 wherein the bottom panel is flat, and the first locking projection and the second locking projection have a distance therebetween in a direction parallel to the flat bottom panel that is greater than a distance between the first through opening and the second through opening in the same direction.
 7. The container of claim 1 wherein the top portion includes depending walls extending downwardly from peripheral edges of the top panel.
 8. The container of claim 7 wherein the depending walls are oblique to the top panel.
 9. The container of claim 1 wherein the first and second locking projections are formed of a folded sheet of material.
 10. A container comprising: a bottom portion including: a bottom panel; a first wall extending from a first edge of the bottom panel; a second wall extending from a second edge of the bottom panel; a third wall extending from a third edge of the bottom panel; a fourth wall extending from a fourth edge of the bottom panel; a first corner between the first wall and the second wall; a second corner between the first wall and the third wall; a third corner between the fourth wall and the second wall; and a fourth corner between the fourth wall and the third wall, whrein an angle between the bottom panel and each of the four walls is greater than 90 degrees and less than 180 degrees; a top portion including; a top panel; a first wall extending from a first edge of the top panel; a second wall extending from a second edge of the top panel; a third wall extending from a third edge of the top panel; and a fourth wall extending from a fourth edge of the top panel, wherein an angle between the top panel and each of the four walls of the top portion is greater than 90 degrees and less than 180 degrees; a first projection extending from at least one of the walls of the bottom portion at the first corner; and a second projection extending from at least one walls of the bottom portion at the second corner, and wherein the first projection and the second projection are received within a first opening and a second opening respectively in the top panel of the top portion.
 11. The container of claim 10 wherein a distance between outer points of the first projection and the second projection is greater than a distance between an outside edge of the first opening and an opposite outside edge of the second opening such that when the projections are inserted, the projections are deformed by the top portion.
 12. The container of claim 11 wherein the distance between an end point of the first projection and an end point of the second projection is less than a distance between bottom edges two opposite walls of the top portion.
 13. The container of claim 10 further comprising a third projection extending from the third corner of the bottom portion and a fourth projection extending from the fourth corner of the bottom portion, wherein top panel of the top portion further comprises a third opening configured to receive the third projection and a fourth opening configured to receive the fourth opening.
 14. The container of claim 10 wherein the bottom portion and the top portion are distinct structures.
 15. The container of claim 10 wherein the first projection is folded at the first corner to have a generally L-shaped cross section.
 16. A container comprising: a bottom portion comprising: a generally flat bottom panel; at least one generally upstanding side wall, the at least one upstanding side wall being oblique to the bottom panel; a first projection extending from a top edge of the at least one side wall; and a second projection extending from the top edge of the at least one side wall such that spacing between the first projection and the second projection in a direction parallel to the bottom panel becomes greater as the projections extend upwardly; and a top portion having a first opening configured to receive the first projection and a second opening configured to receive the second projection.
 17. The container of claim 16 wherein a distance between a top end of the first projection and a top end of the second projection is greater than a distance between the first opening and the second opening.
 18. The container of claim 16 wherein the top portion comprises a top panel and at least one depending sidewall that is oblique to the top panel. 